Microbes may be inactivated in different ways depending on the purpose for inactivating them. The approach differs depending on whether the purpose is to prevent growth of microorganisms, to inhibit further growth or to reduce and eliminate the microorganism. Additionally the approach differs depending on where the microorganism is located such as in a liquid, on a surface, within a mammalian body etc. However, there are certain conditions which need to be fulfilled which are independent of the criteria mentioned above. In addition to being highly effective, the composition to be used should be non-toxic, non-allergenic, environmentally friendly and possible to manufacture at reasonable cost.
One example of such an agent is propane-1,2-diol (propylene glycol), which is the only diol widely used to inactivate microorganisms in dermatology. In addition, pentane-1,5-diol has been used as a component in topical pharmaceutical compositions, where it has been shown to increase the percutaneous absorption of active substances more efficiently than propane-1,2-diol. The water binding capacity of pentane-1,5-diol is largely comparable to that of propane-1,2-diol, but it penetrates more efficiently into the deepest parts of stratum corneum of the skin. In addition, pentane-1,5-diol is cosmetically attractive, presents a low risk for skin and eye irritation compared to other diols, has low toxicity and is odourless.
WO 03/035021 discloses a topical composition for skin care or administration of a pharmacologically active agent in form of a lotion, cream or similar that comprises from 5% to 70% by weight of pentane-1,5-diol in a cosmetically or pharmaceutically acceptable carrier.
Multi-resistance of bacteria to antibiotics is becoming more and more common. In the health sector there is today a mounting concern worldwide regarding the future use of traditional antimicrobials. Alternative methods and approaches have to be used to manufacture affective antimicrobial agents. PCT/SE2004/001001 discloses the in-vitro effect of pentane-1,5-diol against both antibiotic sensitive and multi-resistant gram-positive and gram-negative bacteria. Pentane-1,5-diol was highly effective with minimal inhibitory concentrations (MIC) in the range of 5 to 12.5% against both sensitive as well as multi-resistant aerobic bacteria. The exact mechanism of inhibitory action is unknown; possibly pentane-1,5-diol withdraws water from the bacterial cytoplasma, which makes the cell collapse. Importantly, it seems to be difficult for bacteria to develop resistance against pentane-1,5-diol. The high antimicrobial activity against multi-resistant bacteria has made pentane-1,5-diol an interesting agent for topical antimicrobial therapy in humans and animals.
The use of 2-methyl-pentane-2,4-diol in pharmaceutical compositions for transdermal delivery is disclosed in U.S. Pat. No. 4,855,294 A, U.S. Pat. No. 5,026,556 A, U.S. Pat. Nos. 5,041,439 A, 6,271,219 B1.
However, there is an increasing medical need to identify new antimicrobial compositions, which can be effectively used to inactivate microorganisms. In particular there is a growing list of microorganisms, such as bacteria, virus and fungi, which become resistant to antibiotics. Additionally, there is an increasing population of individuals becoming allergenic against a variety of antibiotics or preservative components used in antibiotic preparations, which also demands that novel compositions are developed which can be used as alternatives to conventional technologies.